Understanding Baseinlineformset and inlineformset_factory.

[NIKHIL RAJGARHIA]

Hi All,

I am unable to understand the below logic for 'BaseInlineFormSet' and 'inlineformset_factory'.

1. What is the use of 'formset' in 'inlineformset_factory'?

2. What is the use of validation inside 'BaseInlineFormSet'? How it works? I haven't seen any implementation like this validation in normal forms.

As I have only worked with general forms, I was exploring on 'formset', but, couldn't understand this piece of example. I know 'formset' is used to create multiple forms on the same page.

AnswerFormSet = inlineformset_factory( #this will be an instance of the form

        Question,  # parent model

        Answer,  # base model or child model

        formset=BaseAnswerInlineFormSet,

        fields=('text', 'is_correct'),

        min_num=2,

        validate_min=True,

        max_num=10,

        validate_max=True

    )

class BaseAnswerInlineFormSet(forms.BaseInlineFormSet):

    def clean(self):

        super().clean()

        has_one_correct_answer = False

        for form in self.forms:

            if not form.cleaned_data.get('DELETE', False):

                if form.cleaned_data.get('is_correct', False):

                    has_one_correct_answer = True

                    break

        if not has_one_correct_answer:

            raise ValidationError('Mark at least one answer as correct.', code='no_correct_answer')

Thank you in advance.

[NIKHIL RAJGARHIA]

Any hint on the above doubt will work fine.